Mapping viruses in non-malignant tonsils, nasal polyps, sinonasal inverted papilloma and laryngeal cancer

Abstract: Background: The upper respiratory tract is exposed to viruses, which can lead to infection and cancer development. We chose to study common and/or chronic diseases along with common and cancer related viruses in the upper airway. High-risk human papillomavirus (HPV) causes cancer in tonsils and base of tongue, and Epstein-Barr virus (EBV) in the nasopharynx. p16 is used as a site-specific tumor marker for HPV. Human cytomegalovirus (HCMV) and human adenovirus (HAdV) are proposed to be oncomodulatory. It is unclear what significance these viruses have in benign tonsillar disease, chronic rhinosinusitis with nasal polyps (CRSwNP), sinonasal inverted papillomas (SIP) and laryngeal squamous cell carcinoma (LSCC). If virus is identified, it could make possible the use of current vaccines in prevention and treatment, as well as protection of healthcare providers.Material and Methods: We analyzed 40 benign tonsils, 45 paired nasal polyp and healthy nasal mucosa samples, 53 SIP and 78 LSCC samples. We used PCR/microarrays (PapilloCheck®) for HPV detection and genotyping, immunohistochemistry (IHC) for p16 expression and real-time PCR for EBV, HCMV and HAdV detection. Additionally, Epstein-Barr encoding region (EBER) in situ hybridization (ISH) was used for EBV localization and count.Results: HPV and p16 were not co-expressed, and p16 levels were low in benign tonsils, nasal polyps, and paired controls. Also, 9% of LSCC samples were high-risk HPV 16 positive and over-expressed p16.EBV-positive cells were detected in 65% of the tonsils, nasal polyps (36%) versus controls (12%), 30% of SIP cases and 33% of LSCC samples.Conclusions: EBV is commonly identified in benign tonsils, nasal polyps, SIP and LSCC, when using sensitive and robust detection methods. At the same time, viral infection with HPV, HCMV or HAdV appears to be uncommon in these conditions. p16 does not emerge as a reliable marker for HPV infection in LSCC.